The invention concerns a liquid coating device for applying liquid to moving surfaces, with a rotor housing comprising at least one or more spray rotors, each spray rotor comprising a drive means, a drive shaft projecting from the drive means, a bearing element for the drive shaft and a spray disk driven by the drive shaft, wherein the spray disk is substantially formed like a pan and has an upwardly facing opening.
DE-A-20 58 667 discloses a device for applying liquid onto moving surfaces which comprises a rotor housing containing a plurality of spray disks. These spray disks each have a vertical axis of rotation, wherein the axes of rotation terminate at their upper ends in a V-belt pulley. This V-belt pulley is driven via one single V-belt. A bearing box is located below this drive which bears the entire rotation unit on the rotor housing. The pan-shaped spray disk which is open at the top and into which the liquid to be sprayed is introduced via a line, is located below this bearing box.
It has turned out that cleaning of the overall spray device is relatively complicated since dismantling of the spray disk requires dismantling of the belt pulley and of the entire bearing. The bearing is moreover located in the spray region of the liquid to be sprayed which can reduce the service life of the bearing elements.
It is therefore the underlying purpose of the present invention to provide a liquid coating device of the above-mentioned type with which cleaning of the spray disk and of the entire spray region is considerably facilitated and which has a longer service life.
This object is achieved in accordance with the invention with a liquid coating device of the above-mentioned type in that, in the predominant position of use of the device, the spray disk is disposed substantially above the drive means.
In another solution, the opening of the spray disk faces away from the drive means.
In yet another solution, the rotor housing comprises a separating wall which separates the bearing element from the spray disk.
The above-mentioned variants of the inventive application device considerably facilitate cleaning of the spray disk and of the entire spray region, since the spray disk is disposed above the drive means and can be accessed from the top. Only the lid of the rotor housing must be removed to provide access to the spray disks from above. Dismantling of the entire drive, in particular of the belt pulley, is no longer required since it is located below the spray disk. The easily accessible spray disks can be cleaned and also exchanged e.g. by removing them from the drive shaft.
The bearings are protected since the opening of the spray disk faces away from the drive means. The liquid is thrown from the spray disk substantially outwardly and upwardly, and therefore the bearing or its annular clearance is no longer in the direct flow or spray region of the liquid to be sprayed.
Finally, the third embodiment of the invention has the advantage that the region where the spray disk is located and where the liquid is sprayed and whirled, is separated by a separating wall from the bearing element. For this reason, the bearing element and therefore the entire drive unit are separated from the spray disk (located in a separate space). This embodiment is particularly advantageous when aggressive liquids are used since they are prevented from reaching the bearing and drive parts.
In a further development, the spray disk is mounted on the drive shaft. This has the substantial advantage that the spray disk can be replaced by a new or a different spray disk in a relatively easy fashion such that when e.g. the spray disk is soiled, it can be removed and a new spray disk can be mounted on the drive shaft. Exchange of spray disks moreover permits relatively easy adjustment to the liquid to be sprayed or to the amount of liquid.
To ensure safe connection between the spray disk and drive shaft, rotary carriers are provided which are disposed on the drive shaft or on the spray disk and are adapted to the respective other component. These rotary carriers ensure easy coupling between the spray disk and the drive shaft and also slip-free rotational carrying along of the spray disk.
In order to avoid intercepting the liquid sprayed in the spraying direction, the rotor housing has a liquid tub extending above the drive means and below the spray disk. This tub is advantageously formed as separating wall and prevents liquid, spray or the like from passing directly from the region of the spray disk to the drive region accommodating the bearing. The liquid tub which collects the liquid not sprayed, divides the rotor housing into a dry drive region and a moist spray region.
Advantageously, a liquid supply is provided from above and feeds onto the spray disk. This liquid supply is located exclusively within the region where the spray disks are provided and the liquid line does not have to be guided through a separating wall or a liquid tub.
In one embodiment, the liquid is advantageously supplied centrally on the spray disk. This is substantially advantageous in that the liquid which is supplied exactly at the center, is uniformly distributed on the spray disk.
In a preferred embodiment, the bearing element has an inner ring connected to the rotor housing and an outer ring connected to the drive shaft. The inner ring and the outer ring are thereby parts of a roller or sliding bearing. The inner ring is preferably connected to the liquid tub of the rotor housing via a sleeve. Via this sleeve, the inner ring is rigidly clamped to the liquid tub or the separating wall of the rotor housing, whereas the outer ring seats in a corresponding receiving bore of the drive means. The drive belts engage the outside, i.e. the periphery, of this drive means and the drive means is provided with the central drive shaft which is guided without contact through the sleeve to drive the spray disk.
The sleeve preferably has a cover which overlaps and covers the upper side of the inner ring and outer ring of the bearing. This prevents e.g. condensed liquid from dripping into the bearing from above.
In accordance with one preferred embodiment, the lower end of the sleeve and/or the drive means may be provided with a liquid outlet such that the liquid entering the sleeve can be easily drained from the bottom. A further liquid outlet is also provided at which the edge of the cover terminates. This liquid outlet may be provided within the bearing element to prevent liquid dripping from the cover from being guided past the bearing element and onto the belt pulley. The overall bearing element may be provided with a labyrinth for leaking liquid. This labyrinth prevents liquid from entering the bearing and ensures that the liquid is quickly guided out of the bearing element.
In a further development, the spray disk has a downwardly extending apron on its lower side which is immersed into a liquid bath of a liquid tub. The apron immersed into the liquid bath serves as a vapor lock, preventing liquid vapor from entering the bearing element via the sleeve.